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 程式師世界 >> 編程語言 >> JAVA編程 >> 關於JAVA >> java解析dbf之經由過程javadbf包生成和讀取dbf文件

java解析dbf之經由過程javadbf包生成和讀取dbf文件

編輯:關於JAVA

java解析dbf之經由過程javadbf包生成和讀取dbf文件。本站提示廣大學習愛好者:(java解析dbf之經由過程javadbf包生成和讀取dbf文件)文章只能為提供參考,不一定能成為您想要的結果。以下是java解析dbf之經由過程javadbf包生成和讀取dbf文件正文


靜態計劃處理矩陣連乘成績,隨機發生矩陣序列,輸入形如((A1(A2A3))(A4A5))的成果。

代碼:

#encoding: utf-8
=begin
author: xu jin, 4100213
date: Oct 28, 2012
MatrixChain
to find an optimum order by using MatrixChain algorithm
example output:
The given array is:[30, 35, 15, 5, 10, 20, 25]
The optimum order is:((A1(A2A3))((A4A5)A6))
The total number of multiplications is: 15125

The random array is:[5, 8, 8, 2, 5, 9]
The optimum order is:((A1(A2A3))(A4A5))
The total number of multiplications is: 388 
=end

INFINTIY = 1 / 0.0
p = [30, 35, 15, 5, 10, 20, 25]
m, s = Array.new(p.size){Array.new(p.size)}, Array.new(p.size){Array.new(p.size)}

def matrix_chain_order(p, m, s)
   n = p.size - 1
   (1..n).each{|i| m[i][i] = 0} 
   for r in (2..n) do
     for i in (1..n - r + 1) do
       j = r + i - 1
       m[i][j] = INFINTIY
       for k in (i...j) do
         q = m[i][k] + m[k + 1][j] + p[i - 1] * p[k] * p[j]                  
         m[i][j], s[i][j] = q, k if(q < m[i][j]) 
       end
     end
   end
end 

def print_optimal_parens(s, i, j)
   if(i == j) then
    print "A" + i.to_s
   else 
    print "("
    print_optimal_parens(s, i, s[i][j])
    print_optimal_parens(s, s[i][j] + 1, j)
    print ")"
   end
end

def process(p, m, s)
   matrix_chain_order(p, m, s)
   print "The optimum order is:"
   print_optimal_parens(s, 1, p.size - 1)
   printf("\nThe total number of multiplications is: %d\n\n", m[1][p.size - 1])
end

puts "The given array is:" + p.to_s
process(p, m, s)

#produce a random array
p = Array.new
x = rand(10)
(0..x).each{|index| p[index] = rand(10) + 1}
puts "The random array is:" + p.to_s
m, s = Array.new(p.size){Array.new(p.size)}, Array.new(p.size){Array.new(p.size)}
process(p, m, s)


nbsp;      {  
              DBFField field = reader.getField(i);
              System.out.println(field.getName());
            }  
            Object[] rowValues;  
            //一條條掏出path文件中記載  
            while((rowValues = reader.nextRecord()) != null)
            {  
              for( int i=0; i<rowValues.length; i++)
              {  
                System.out.println(rowValues[i]);
              }  
            }  
          }  
          catch(Exception e)   
          {  
          e.printStackTrace(); 
          } 
          finally 
          {  
          try{  
               fis.close();
          }catch(Exception e){} 
          }
    }  

 

 public static void writeDBF(String path)
 {

  OutputStream fos = null;
  try 
  {  
      //界說DBF文件字段  
      DBFField[] fields = new DBFField[3];
      //分離界說各個字段信息,setFieldName和setName感化雷同,
      //只是setFieldName曾經不建議應用  
      fields[0] = new DBFField();  
      //fields[0].setFieldName("emp_code");
      fields[0].setName("semp_code");  
      fields[0].setDataType(DBFField.FIELD_TYPE_C);  
      fields[0].setFieldLength(10);  

      fields[1] = new DBFField();  
      //fields[1].setFieldName("emp_name");
      fields[1].setName("emp_name");  
      fields[1].setDataType(DBFField.FIELD_TYPE_C);  
      fields[1].setFieldLength(20);  

      fields[2] = new DBFField();  
      //fields[2].setFieldName("salary");
      fields[2].setName("salary"); 
      fields[2].setDataType(DBFField.FIELD_TYPE_N);  
      fields[2].setFieldLength(12);  
      fields[2].setDecimalCount(2);  

      //DBFWriter writer = new DBFWriter(new File(path));  

      //界說DBFWriter實例用來寫DBF文件  
      DBFWriter writer = new DBFWriter();
      //把字段信息寫入DBFWriter實例,即界說表構造 
      writer.setFields(fields);  
      //一條條的寫入記載  
      Object[] rowData = new Object[3];
      rowData[0] = "1000";  
      rowData[1] = "John";  
      rowData[2] = new Double(5000.00);
      writer.addRecord(rowData);  

      rowData = new Object[3]; 
      rowData[0] = "1001"; 
      rowData[1] = "Lalit";
      rowData[2] = new Double(3400.00);  
      writer.addRecord(rowData);  

      rowData = new Object[3];
      rowData[0] = "1002";  
      rowData[1] = "Rohit"; 
      rowData[2] = new Double(7350.00); 
      writer.addRecord(rowData);  

      //界說輸入流,並聯系關系的一個文件  
      fos = new FileOutputStream(path);
      //寫入數據  
      writer.write(fos);  

      //writer.write(); 
  }catch(Exception e)  
  {  
      e.printStackTrace();  
  }  
  finally 
  {  
      try{  
      fos.close();
      }catch(Exception e){}
  }
 }

 public static void main(String[] args){
  String path ="E:\\tmp\\2\\xx.dbf";
  try {
   InputStream fis = new FileInputStream(path);
   DBFReader reader = new DBFReader(fis);
   int fieldsCount = reader.getFieldCount();
            System.out.println("字段數:"+fieldsCount);

            DBFField[] df = new DBFField[fieldsCount+2];
            for( int i=0; i<fieldsCount; i++)   
            {  
              df[i] = reader.getField(i);
              System.out.println("field"+i+":"+df[i].getName());
            }
            df[fieldsCount] = new DBFField();
            df[fieldsCount].setName("add1");
            df[fieldsCount].setDataType(DBFField.FIELD_TYPE_C);
            df[fieldsCount].setFieldLength(10);
            df[fieldsCount+1] = new DBFField();
            df[fieldsCount+1].setName("add2");
            df[fieldsCount+1].setDataType(DBFField.FIELD_TYPE_C);
            df[fieldsCount+1].setFieldLength(10);

            DBFWriter writer = new DBFWriter();
            writer.setFields(df);

            Object[] rowValues;
            Object[] rowValues1 = new Object[fieldsCount+2];
            //一條條掏出path文件中記載  
            while((rowValues = reader.nextRecord()) != null)
            {
              for(int i=0;i<fieldsCount;i++){
               rowValues1[i] = rowValues[i];
              }
              rowValues1[fieldsCount]="x";
              rowValues1[fieldsCount+1]="xx";
              writer.addRecord(rowValues1);
            }

           
            path ="E:\\tmp\\2\\test2.dbf";
            OutputStream fos = new FileOutputStream(path);
          //寫入數據  
          writer.write(fos);  

          System.out.println("OVER");

           
  } catch (FileNotFoundException | DBFException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }

}

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